— Have you ever come here before?

— No, it is the first time that I______ to this city.

[      ]

A. have been

B. had been

C. came

D. come

适用于肥胖糖尿病人的降糖药是（）。

A.甲苯磺丁脲

B.格列齐特

C.氯磺丙脲

D.格列喹酮

E.二甲双胍